Question: Multiply. $0.86 \times 2.2=$
Answer: $86 \times 22$ and $0.86\times 2.2$ multiply the same digits in the same order. So, the product of both problems will also have the same digits in the same order. Let's multiply $86 \times 22$. Then we can estimate to place the decimal point in the product of $0.86 \times 2.2$. $\begin{aligned} 86&\\ \underline{ \times 22}&\\ 12}& {2} \times {6\text{ ones}}\\ 160}& {2} \times {8\text{ tens}}\\ 120}& {20} \times {6\text{ ones}}\\ \underline{+1{,}600}}& {20} \times {8\text{ tens}}\\ 1{,}892 \end{aligned}$ $86\times22=1{,}892$ Let's estimate to place the decimal in $0.86 \times 2.2$. $\begin{aligned} 0.86 \times 2.2 &\approx 1\times 2\\\\ &\approx 2 \end{aligned}$ Where can we place the decimal in $1{,}892$ to get a product close to $2$ ? $0.86\times2.2=1.892$